1. Field of the Invention
The present invention relates to an electronic cassette for use in radiography.
2. Description of the Related Art
An electronic cassette has been widely used in medical radiography, for example, in X-ray photography. The electronic cassette is a portable X-ray image detector which has a built-in image detection unit (flat panel detector (FPD)) for detecting an X-ray image of a photographic subject (such as a patient) inside a portable housing having a flat and rectangular parallelepiped shape.
The electronic cassette is used not only by being set on a dedicated photographing stand holder, but also by being attached to an existing photographing stand holder for a film cassette, an IP cassette and a CR cassette. Furthermore, in order to photograph a site which is unlikely to be photographed by using a stationary type which has an built-in X-ray image detector unremovable from the photographing stand, a user places the electronic cassette on a bed, or causes the electronic cassette to be held by a patient's own hand. In addition, in order to photograph an aged person in convalescence at home or emergency patients due to accidents, disasters or the like, in some cases, the electronic cassette is used outside hospitals which do not have facilities for the photographing stand. Since the electronic cassette is also used without being attached to the photographing stand holder, enhanced mobility and installation flexibility are required. In addition, since there is a possibility that the electronic cassette may directly come into contact with the patients, it is also important that the electronic cassette does not give discomfort to the patients when in contact.
JP2002-082172A discloses an electronic cassette that has a rectangular parallelepiped housing in which a chamfered portion formed from a plane tilted to a side surface and a rear surface is disposed between the side surface and the rear surface of the housing. The housing has a shape as if a corner at an intersection of the side surface and the rear surface is cut off in a planar shape. The chamfered portion is a tilted plane and the rear surface is also the plane. Accordingly, a boundary between the chamfered portion and the rear surface has an angle, although the angle is an obtuse angle. For example, when the electronic cassette is placed on a flat surface (hereinafter, referred to as an installation surface) in a state where the rear surface faces downward, a finger is allowed to enter a gap between the chamfered portion and the installation surface by disposing the chamfered portion described above. Accordingly, the finger is easily hooked on an end portion of the housing and thus it is easy to lift the electronic cassette up. In addition, since the chamfered portion is disposed between the side surface and the rear surface, as compared to the housing having a corner of 90° at the intersection of the side surface and the rear surface, the patient's contact feeling becomes softer when the end portion of the housing comes into contact with the patients.